Attachment 18287 Details for Bug 15635 – patch for 4.20

[patch] patch for 4.20

0001-Do-not-fail-checksums-for-RFC8009-types.patch (text/plain), 4.81 KB, created by Andreas Schneider on 2024-04-16 07:25:23 UTC

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Creator: Andreas Schneider

Created: 2024-04-16 07:25:23 UTC

Size: 4.81 KB

patch

obsolete

>From a92e9c7c2873efdb1257e87e92a83ed4c75d25e8 Mon Sep 17 00:00:00 2001
>From: Alexander Bokovoy <ab@samba.org>
>Date: Thu, 22 Jun 2023 09:56:12 +0300
>Subject: [PATCH] Do not fail checksums for RFC8009 types
>
>While Active Directory does not support yet RFC 8009 encryption and
>checksum types, it is possible to verify these checksums when running
>with both MIT Kerberos and Heimdal Kerberos. This matters for FreeIPA
>domain controller which uses them by default.
>
>[2023/06/16 21:51:04.923873, 10, pid=51149, effective(0, 0), real(0, 0)]
>../../lib/krb5_wrap/krb5_samba.c:1496(smb_krb5_kt_open_relative)
>  smb_krb5_open_keytab: resolving: FILE:/etc/samba/samba.keytab
>[2023/06/16 21:51:04.924196,  2, pid=51149, effective(0, 0), real(0, 0),
>class=auth] ../../auth/kerberos/kerberos_pac.c:66(check_pac_checksum)
>  check_pac_checksum: Checksum Type 20 is not supported
>[2023/06/16 21:51:04.924228,  5, pid=51149, effective(0, 0), real(0, 0),
>class=auth] ../../auth/kerberos/kerberos_pac.c:353(kerberos_decode_pac)
>  PAC Decode: Failed to verify the service signature: Invalid argument
>
>BUG: https://bugzilla.samba.org/show_bug.cgi?id=15635
>
>Signed-off-by: Alexander Bokovoy <ab@samba.org>
>Reviewed-by: Andreas Schneider <asn@samba.org>
>Reviewed-by: Andrew Bartlett <abartlet@samba.org>
>(cherry picked from commit 8e931fce126e8c1128da893c806702731c08758a)
>---
> auth/kerberos/kerberos_pac.c | 47 +++++++++++++++++++++---------------
> lib/krb5_wrap/krb5_samba.h   | 28 +++++++++++++++++++++
> 2 files changed, 56 insertions(+), 19 deletions(-)
>
>diff --git a/auth/kerberos/kerberos_pac.c b/auth/kerberos/kerberos_pac.c
>index ae4557bbd6f..b6272ac15eb 100644
>--- a/auth/kerberos/kerberos_pac.c
>+++ b/auth/kerberos/kerberos_pac.c
>@@ -33,6 +33,7 @@
> #include "librpc/gen_ndr/auth.h"
> #include "auth/common_auth.h"
> #include "auth/kerberos/pac_utils.h"
>+#include "lib/krb5_wrap/krb5_samba.h"
> 
> krb5_error_code check_pac_checksum(DATA_BLOB pac_data,
> 					  struct PAC_SIGNATURE_DATA *sig,
>@@ -44,26 +45,34 @@ krb5_error_code check_pac_checksum(DATA_BLOB pac_data,
> 	krb5_keyusage usage = 0;
> 	krb5_boolean checksum_valid = false;
> 	krb5_data input;
>-
>-	switch (sig->type) {
>-	case CKSUMTYPE_HMAC_MD5:
>-		/* ignores the key type */
>-		break;
>-	case CKSUMTYPE_HMAC_SHA1_96_AES_256:
>-		if (KRB5_KEY_TYPE(keyblock) != ENCTYPE_AES256_CTS_HMAC_SHA1_96) {
>-			return EINVAL;
>-		}
>-		/* ok */
>-		break;
>-	case CKSUMTYPE_HMAC_SHA1_96_AES_128:
>-		if (KRB5_KEY_TYPE(keyblock) != ENCTYPE_AES128_CTS_HMAC_SHA1_96) {
>-			return EINVAL;
>+	size_t idx = 0;
>+	struct {
>+		krb5_cksumtype cksum_type;
>+		krb5_enctype enc_type;
>+	} supported_types[] = {
>+		{CKSUMTYPE_HMAC_SHA1_96_AES_256, ENCTYPE_AES256_CTS_HMAC_SHA1_96},
>+		{CKSUMTYPE_HMAC_SHA1_96_AES_128, ENCTYPE_AES128_CTS_HMAC_SHA1_96},
>+		/* RFC8009 types. Not supported by AD yet but used by FreeIPA and MIT Kerberos */
>+		{CKSUMTYPE_HMAC_SHA256_128_AES128, ENCTYPE_AES128_CTS_HMAC_SHA256_128},
>+		{CKSUMTYPE_HMAC_SHA384_192_AES256, ENCTYPE_AES256_CTS_HMAC_SHA384_192},
>+		{0, 0},
>+	};
>+
>+	for(idx = 0; supported_types[idx].cksum_type != 0; idx++) {
>+		if (sig->type == supported_types[idx].cksum_type) {
>+			if (KRB5_KEY_TYPE(keyblock) != supported_types[idx].enc_type) {
>+				return EINVAL;
>+			}
>+			/* ok */
>+			break;
> 		}
>-		/* ok */
>-		break;
>-	default:
>-		DEBUG(2,("check_pac_checksum: Checksum Type %"PRIu32" is not supported\n",
>-			sig->type));
>+	}
>+
>+	/* do not do key type check for HMAC-MD5 */
>+	if ((sig->type != CKSUMTYPE_HMAC_MD5) &&
>+	    (supported_types[idx].cksum_type == 0)) {
>+		DEBUG(2,("check_pac_checksum: Checksum Type %d is not supported\n",
>+			(int)sig->type));
> 		return EINVAL;
> 	}
> 
>diff --git a/lib/krb5_wrap/krb5_samba.h b/lib/krb5_wrap/krb5_samba.h
>index e158a404dea..795106453c9 100644
>--- a/lib/krb5_wrap/krb5_samba.h
>+++ b/lib/krb5_wrap/krb5_samba.h
>@@ -88,6 +88,34 @@
> #define CKSUMTYPE_HMAC_SHA1_96_AES_256 CKSUMTYPE_HMAC_SHA1_96_AES256
> #endif
> 
>+/*
>+ * RFC8009 encryption types' defines have different names:
>+ *
>+ * KRB5_ENCTYPE_AES128_CTS_HMAC_SHA256_128 in Heimdal
>+ * ENCTYPE_AES128_CTS_HMAC_SHA256_128 in MIT
>+ *
>+ * and
>+ *
>+ * KRB5_ENCTYPE_AES256_CTS_HMAC_SHA384_192 in Heimdal
>+ * ENCTYPE_AES256_CTS_HMAC_SHA384_192 in MIT
>+ */
>+#if !defined(ENCTYPE_AES128_CTS_HMAC_SHA256_128)
>+#define ENCTYPE_AES128_CTS_HMAC_SHA256_128 KRB5_ENCTYPE_AES128_CTS_HMAC_SHA256_128
>+#endif
>+#if !defined(ENCTYPE_AES256_CTS_HMAC_SHA384_192)
>+#define ENCTYPE_AES256_CTS_HMAC_SHA384_192 KRB5_ENCTYPE_AES256_CTS_HMAC_SHA384_192
>+#endif
>+
>+/*
>+ * Same for older encryption types, rename to have the same defines
>+ */
>+#if !defined(ENCTYPE_AES128_CTS_HMAC_SHA1_96)
>+#define ENCTYPE_AES128_CTS_HMAC_SHA1_96 KRB5_ENCTYPE_AES128_CTS_HMAC_SHA1_96
>+#endif
>+#if !defined(ENCTYPE_AES256_CTS_HMAC_SHA1_96)
>+#define ENCTYPE_AES256_CTS_HMAC_SHA1_96 KRB5_ENCTYPE_AES256_CTS_HMAC_SHA1_96
>+#endif
>+
> /*
>  * KRB5_KU_OTHER_ENCRYPTED in Heimdal
>  * KRB5_KEYUSAGE_APP_DATA_ENCRYPT in MIT
>-- 
>2.44.0
>

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Attachments on bug 15635: 18287